We present herein localized galvanostatic and potentiodynamic measurements on lithium iron phosphate (LFP) particles, using the combination of a scanning micropipette contact method and scanning electron microscopy (SEM). The proposed technique allows small substrate areas (~10 µm in diameter) decorated with LFP particles to be probed within a lithium electrolyte solution in organic carbonate solvents (0.1 M LiClO4 in propylene carbonate in the present study). SEM images of the scanned area allow the correlation of each electrochemical response to the number, and volume of the probed particles. Under favorable conditions, single particles are found within the measurement areas, thus enabling the determination of single particle properties in an anaerobic environment without the additional complications arising from the presence of binders and electronically conductive fillers. The ability to analyze a material with complementary experimental techniques at the single particle level should create new opportunities for fundamental studies and for the quality control of granular materials.

No abstract

We report a redox-responsive liposomal system capable of oxidatively triggered disassembly. We describe the synthesis, electrochemical characterization, and incorporation into vesicles of an alternative redox lipid with significantly improved synthetic efficiency and scalability compared to a ferrocene-appended phospholipid previously employed by our group in giant vesicles. The redox-triggered disassembly of both redox lipids is examined in nanosized liposomes as well as the influence of cholesterol mole fraction on liposome disassembly and suitability of various chemical oxidants for in vitro disassembly experiments. Electronic structure density functional theory calculations of membrane-embedded ferrocenes are provided to characterize the role of charge redistribution in the initial stages of the disassembly process.

We are reporting the application of scanning electrochemical cell microscopy to probe and identify nanometric defects in a multilayered aryl film formed by aryldiazonium reduction. We have determined by numerical simulation that, due to pipette geometry restrictions, the best sensitivity towards pinhole size can be obtained when measuring small pinholes (� 10 nm) with moderately large pipette sizes (ca. 500 nm).

Composite electrodes can significantly improve the performance of an electrochemical device by maximizing surface area and active material loading. Typically, additives such as carbon are used to improve conductivity and a polymer is used as a binder, leading to a heterogeneous surface film with thickness on the order of 10s of micrometers. For such composite electrodes, good ionic conduction within the film is critical to capitalize on the increased loading of active material and surface area. Ionic conductivity within a film can be tricky to measure directly, and homogenization models based on porosity are often used as a proxy. SICM has traditionally been a topography-mapping microscopy method for which we here outline a new function and demonstrate its capacity for measuring ion conductivity within a lithium-ion battery film.